Advent of Muslims in India: Latest excavation has established that Indo-Arab relations go back to 2500 B.C. Arabs had settled in southern India long before the preaching of Islam. Islam had brought about a revolution in the Arabian Peninsula but is not certain when the Muslims first arrived in India. Without doubt they must have reached here before the invasion of Sind by Muhammad bin Qasim in 712 A.D. Some Arab Muslims might have settled in Ceylon during the lifetime of the Prophet (d. 632 A.D.).
Facts and legends have been mixed up in reports about the first batch of Muslim merchants and sailors who visited southern India after death of the Prophet. This took place in the seventh century and in the eighth and ninth centuries many more Arab and Persian Muslim settled in different parts of eastern and western coasts of south India. The hospitable Rajas of the south allowed them to settle, build mosques and marry indigenous women. Slowly and gradually, more and more Muslim travelers, merchants and sailors settled in these regions.
The presence of a number of Muslims enjoying complete freedom of religion with several newly-built mosques is attested by the Arab merchants, geographers, travelers and sailors who have left almost contemporary written accounts of these regions.